After all, Hoyer said, President Barack Obama should have had more "precision" when he told the American people that if they liked their health insurance, they could keep it under the new health law — a promise that has not been entirely fulfilled as the Obamacare rollout continues.

But hours later, Hoyer was ready to say he would, without question, oppose the bill.

Hoyer spokeswoman Stephanie Young told CQ Roll Call that, as Hoyer said at the briefing, he was waiting to make a decision until he saw the final text; there was some possibility that Upton was making revisions to the language that would have made the bill either more palatable or more onerous.

A House Democratic aide said that ultimately no changes were made, clearing the way for Hoyer to join his colleagues in opposition.

Confirmation from Hoyer's office on the No. 2 Democrat's position on the Upton bill came shortly after an aide to House Democratic leaders sent out a statement announcing leadership's collective opposition.

"The Upton legislation would create a new insurance market where people with pre-existing conditions would be discriminated against and women would pay more," said the aide. "The bill would increase premiums and undermine the health reform law. While we have not seen the final text, the leadership will oppose this legislation as it is the 46th attempt to repeal or undermine the Affordable Care Act."

There has been no indication of whether House Democratic leaders will launch a formal whip operation against the legislation, a touchy subject for vulnerable members of the caucus for whom a "yes" vote could bolster their re-election chances in 2014.